About pkrrating
3B). R526 with the loop involving αJ and αI anchors the C-terminal percentage of the activation loop by forming a salt bridge with E458 at The bottom of αEF. Q459 stabilizes the HRD motif by a hydrogen bond to the main chain carbonyl of R413. The tip on the activation segment is stabilized by a hydrogen bond between Y454 and E480 from αF. from